The present invention relates generally to a method for displaying radiotherapy treatment plans.
About fifty or sixty percent of patients with cancer require radiation at sometime during their lifetime. Basically two types of radiation treatment exist: external radiation and brachytherapy, or radiation at a short distance. However, other types of radiation therapy (RT) may exist depending on the type of cancer and patient involved in the radiation treatment.
Radiation therapy in the great majority of cases is done in fractions. The therapeutic dose is administered once or several times a day, and distributed over many sessions (fractions). The dose depends primarily on tumor type, but the doctor considers many other factors including whether radiation is given alone or with chemotherapy, whether radiation is given before or after surgery, and the success of surgery and its findings. Moreover, the radiation therapy may involve several targets that require different total doses depending on these factors.
In some instances, for a single target, the fractions are identical in terms of the radiation technique used and dosage applied. However, in other instances, the fractions use different radiation techniques and different dosages at different times for a single target, or multiple targets.
The typical fractionation schedule is 1.8 to 2 grays (Gy) per fraction, with one fraction per day. The typical treatment schedule is five days per week, no weekends. Alternative fractionation schedules also exist. One of the best known is the Continuous Hyperfractionated Accelerated RadioTherapy (CHART) regimen for lung cancer, which uses three smaller fractions per day in the treatment of lung cancer, including weekends. Twice-a-day treatments have also been tried for other sites, such as head and neck cancers. One specific twice-a-day therapy is the boost regimen. With the boost technique, a second fraction is added to “boost” the gross disease during the final approximate two weeks of treatment.
The radiation technique used during one fraction is developed in the form of a treatment (Tx) plan with the aid of a treatment planning system (“TPS”). Such a Tx plan is then made available for the radiation treatment. Specifically, a Tx plan contains geometric and dosimetric data that specifies a course of external beam and/or brachytherapy treatment, such as beam angles, collimator openings, beam modifiers, and brachytherapy channel and source specifications. If not all the fractions involve the same Tx plan, multiple plans are prepared that usually, depending on the fraction number, are added together by the TPS, so that the cumulative therapeutic effect can be assessed from the total dosage distribution.
The goal of treatment planning is to create the best Tx plan for each target. To do so, many plans are created, some of which will never be used. The doctor must choose the best plan, and create the best combination of plans to treat the target(s).
However, current treatment planning systems do not adequately determine the order of executing the various Tx plans. The Digital Imaging and Communications in Medicine (DICOM) RT standard uses a “fraction pattern” concept to determine such order. However, the timing information cannot at present be reproduced adequately. Further, DICOM RT uses the “fraction pattern” concept in a rigid timing scheme.
To solve this problem, the Tx plans generated by a TPS and issued for therapy are exported individually to a so-called “oncology information system” (OIS), where they are sorted “by hand” into correct order in a scheduler. Such a system fails to provide the graphical tools necessary to oversee the consequences of putting Tx plans into the incorrect treatment order. The dosimetrist responsible for selecting the correct Tx plans within the OIS may quite easily put such plans in the wrong order. With this system, errors can only be avoided by adding a time consuming quality control process. Further, it creates a tedious process when various radiation modalities must be mixed with one another.
The inventors have recognized a problem with the current treatment planning systems and methods of ordering Tx plans by an oncology information system. Such systems do not adequately and efficiently determine the order of executing the various Tx plans that may be required to effectively treat a patient, and do not adequately display such information to the user.